Standalone Plug-In: Added missing save state when the standalone app is closed

modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h

@@ -636,6 +636,8 @@ public:
     //==============================================================================
     void closeButtonPressed() override
     {
+        pluginHolder->savePluginState();
+
         JUCEApplicationBase::quit();
     }